# uncompyle6 version 3.2.3
# Python bytecode 3.6 (3379)
# Decompiled from: Python 3.6.8 |Anaconda custom (64-bit)| (default, Feb 21 2019, 18:30:04) [MSC v.1916 64 bit (AMD64)]
# Embedded file name: site-packages\cryptography\hazmat\primitives\asymmetric\utils.py
from __future__ import absolute_import, division, print_function
import warnings
from asn1crypto.algos import DSASignature
import six
from cryptography import utils
from cryptography.hazmat.primitives import hashes


def decode_rfc6979_signature(signature):
    warnings.warn(
        "decode_rfc6979_signature is deprecated and will be removed in a future version, use decode_dss_signature instead.",
        utils.PersistentlyDeprecated,
        stacklevel=2,
    )
    return decode_dss_signature(signature)


def decode_dss_signature(signature):
    data = (DSASignature.load(signature, strict=True)).native
    return (data["r"], data["s"])


def encode_rfc6979_signature(r, s):
    warnings.warn(
        "encode_rfc6979_signature is deprecated and will be removed in a future version, use encode_dss_signature instead.",
        utils.PersistentlyDeprecated,
        stacklevel=2,
    )
    return encode_dss_signature(r, s)


def encode_dss_signature(r, s):
    if not isinstance(r, six.integer_types) or not isinstance(s, six.integer_types):
        raise ValueError("Both r and s must be integers")
    return DSASignature({"r": r, "s": s}).dump()


class Prehashed(object):
    def __init__(self, algorithm):
        if not isinstance(algorithm, hashes.HashAlgorithm):
            raise TypeError("Expected instance of HashAlgorithm.")
        self._algorithm = algorithm
        self._digest_size = algorithm.digest_size

    digest_size = utils.read_only_property("_digest_size")
